linux-kernel - Re: [PATCH] x86: ioremap mptable -v2

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Message-ID: <49AC3C8C.8070702@kernel.org>
Date:	Mon, 02 Mar 2009 12:07:40 -0800
From:	Yinghai Lu <yinghai@...nel.org>
To:	Ingo Molnar <mingo@...e.hu>
CC:	"Kevin O'Connor" <kevin@...onnor.net>,
	"Rafael J. Wysocki" <rjw@...k.pl>,
	Stefan Reinauer <stepan@...esystems.de>,
	linux-kernel@...r.kernel.org, coreboot@...eboot.org
Subject: Re: [PATCH] x86: ioremap mptable -v2

Ingo Molnar wrote:
> * Yinghai Lu <yinghai@...nel.org> wrote:
> 
>> Impact: fix boot with mptable above max_low_mapped
>>
>> try to use early_ioremap it.
>>
>> v2: also get the exact size for reserve_bootmem in case we got big size than 4k
>>
>> Signed-off-by: Yinghai Lu <yinghai@...nel.org>
>> Reported-and-tested-by: Kevin O'Connor <kevin@...onnor.net>
>>
>> ---
>>  arch/x86/kernel/mpparse.c |   20 ++++++++++++++++++--
>>  1 file changed, 18 insertions(+), 2 deletions(-)
>>
>> Index: linux-2.6/arch/x86/kernel/mpparse.c
>> ===================================================================
>> --- linux-2.6.orig/arch/x86/kernel/mpparse.c
>> +++ linux-2.6/arch/x86/kernel/mpparse.c
>> @@ -611,12 +611,20 @@ static void __init __get_smp_config(unsi
>>  		construct_default_ISA_mptable(mpf->feature1);
>>  
>>  	} else if (mpf->physptr) {
>> +		struct mpc_table *mpc;
>> +		unsigned long size;
>>  
>> +		mpc = early_ioremap(mpf->physptr, PAGE_SIZE);
>> +		size = mpc->length;
>> +		apic_printk(APIC_VERBOSE, "  mpc: %lx-%lx\n", (unsigned long)mpf->physptr,
>> +			 mpf->physptr + size);
>> +		early_iounmap(mpc, PAGE_SIZE);
>> +		mpc = early_ioremap(mpf->physptr, size);
> 
> no objections, but this bit of __get_smp_config() needs to be 
> done cleaner - the whole mpf->physptr != 0 bit should probably 
> go into a helper function.
> 

please check

[PATCH] x86: ioremap mptable -v3

Impact: fix boot with mptable above max_low_mapped

try to use early_ioremap it.

v2: also get the exact size for reserve_bootmem in case we got big size than 4k
V3: according to Ingo, seperate get_mpc_size()

Signed-off-by: Yinghai Lu <yinghai@...nel.org>
Reported-and-tested-by: Kevin O'Connor <kevin@...onnor.net>

---
 arch/x86/kernel/mpparse.c |   24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

Index: linux-2.6/arch/x86/kernel/mpparse.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/mpparse.c
+++ linux-2.6/arch/x86/kernel/mpparse.c
@@ -558,6 +558,19 @@ static inline void __init construct_defa
 
 static struct mpf_intel *mpf_found;
 
+static unsigned long __init get_mpc_size(unsigned long physptr)
+{
+	struct mpc_table *mpc;
+	unsigned long size;
+
+	mpc = early_ioremap(physptr, PAGE_SIZE);
+	size = mpc->length;
+	early_iounmap(mpc, PAGE_SIZE);
+	apic_printk(APIC_VERBOSE, "  mpc: %lx-%lx\n", physptr, physptr + size);
+
+	return size;
+}
+
 /*
  * Scan the memory blocks for an SMP configuration block.
  */
@@ -611,12 +624,16 @@ static void __init __get_smp_config(unsi
 		construct_default_ISA_mptable(mpf->feature1);
 
 	} else if (mpf->physptr) {
+		struct mpc_table *mpc;
+		unsigned long size;
 
+		size = get_mpc_size(mpf->physptr);
+		mpc = early_ioremap(mpf->physptr, size);
 		/*
 		 * Read the physical hardware table.  Anything here will
 		 * override the defaults.
 		 */
-		if (!smp_read_mpc(phys_to_virt(mpf->physptr), early)) {
+		if (!smp_read_mpc(mpc, early)) {
 #ifdef CONFIG_X86_LOCAL_APIC
 			smp_found_config = 0;
 #endif
@@ -624,9 +641,12 @@ static void __init __get_smp_config(unsi
 			       "BIOS bug, MP table errors detected!...\n");
 			printk(KERN_ERR "... disabling SMP support. "
 			       "(tell your hw vendor)\n");
+			early_iounmap(mpc, size);
 			return;
 		}
 
+		early_iounmap(mpc, size);
+
 		if (early)
 			return;
 #ifdef CONFIG_X86_IO_APIC
@@ -700,7 +720,7 @@ static int __init smp_scan_config(unsign
 			reserve_bootmem_generic(virt_to_phys(mpf), PAGE_SIZE,
 					BOOTMEM_DEFAULT);
 			if (mpf->physptr) {
-				unsigned long size = PAGE_SIZE;
+				unsigned long size = get_mpc_size(mpf->physptr);
 #ifdef CONFIG_X86_32
 				/*
 				 * We cannot access to MPC table to compute

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